A Fifth Dimension:Dead external links
Like almost all large websites, this wiki also suffers from the phenomenon known as link rot, where external links fail to work after a period of time. Repairing link rot Dead links are unprofessional, and should be fixed on a regular basis. In the case of pages being moved rather than deleted, you can try to find the current location of the resource using a search engine. Dead links of online newspaper articles can be converted to references to off-line sources. Do ''not'' simply remove dead links; they often contain valuable information. However, if you are unsuccessful in finding an alternative source, tag the link with which will notify other editors that the link is dead. The flag also adds the article in question to the category articles with dead external links, which can be removed by removing the deadlink template after the links have either been repaired or removed. It is helpful to also add a note about the dead link on the category's talk page, helping other editors to find and fix the link if possible. Using the template, you may optionally provide a link to the Internet Archive's "Wayback Machine." can create these links for you; use the 'url' and 'date' parameters to specify the URL and date. For example: * → Note that the date parameter defaults to '*'. Error status codes There is a large variety of error codes. You can use the list below to identify or read more about the type of error the dead link has, assisting you in listing the link on the Articles with dead external links category's talk page. Although the sections below contain a short description of the status code in question, please refer to the Wikipedia:list of HTTP status codes for a more complete description. 200 The 200 status code indicates that the link is correctly formed, and retrievable. Although such links do not need correction, they are included here for completeness. 300 Indicates that the website requested more information from the Internet bot so that it could make an appropriate presentation of the content. Although such links are most likely correct, they should probably be double checked. 301 Indicates that the content has been moved permanently, and that the link inside Wikipedia should probably be updated to reflect the new location. Although this should not be changed for all sites as some sites use 301 redirects to redirect pages that change their destination often. 302, 303, 307 Indicates that the content has been temporarily moved, and that the client should continue to use the original link. Although these links should be correct in theory, they are often used by link farms, and should probably be checked. 400 Indicates that the site in question could not understand the bot's request. Although these should hopefully diminish with future revisions of the bot, it may be useful to test them, anyway (low priority). Note: links with anchors and HTML entities should be ignored. 401 The page required authorization, which the bot does not support. The page in question may have included login information, the bot has no way of knowing this. Such links should be fixed if the page does not contain login information. 402 Although not an active status code, the servers used it anyway. It indicates that the server requested payment (in theory) from the client. Such links should be fixed. 403 "Forbidden" - this generally indicates the server software itself cannot access the location where the file would be found, or that access to that location is not permitted from the internet under any circumstance - login or authorization information will not change things. Some for-pay reference sites, such as http://www.jstor.org/, might give partial access in the response (e.g. display the first page), which might still be useful. Often a symptom of link rot. Such links should be fixed. 404, 410 The 404 error is the most common symptom of link rot, and it indicates that the page has not been found. The 410 status code is similar, but indicates that the file has permanently gone. Such links are required by policy to be repaired, perhaps with a link to the Internet Archive, WebCite or by finding the current location of the page if it has been moved without a forwarding redirect. 406 Occurs for a number of reasons, indicates that the client request was unacceptable in some manner. Should probably be fixed. 409 Indicates some sort of error that the client needs to resolve. Should probably be fixed. 423 Although not an active status code, servers use it to indicate some sort of "Locked" error. 425 Another non-active status code from a single server, http://www.worldofspectrum.org/. The message it returned at that time was "Mirroring Denied", but those links work OK now. See also Apache docs which indicate a message of "No code", indicating a server misconfiguration. 5xx Indicates there was some sort of internal server error. This could be the result of a malformed bot HTTP request, or numerous other reasons. Should be examined to determine whether the site is suffering from some sort of permanent problem with the link in question. NA - Unsupported protocol Indicates that the link was used a communications protocol such as IRC, Gopher, etc. that the bot is not capable of resolving. Should be checked as to whether the resource type is correct (e.g. htttp://www.wikipedia.org instead of http). NA - Unknown error Indicates that the bot had some sort of difficulty resolving the link in question. Could be caused by a number of errors: DNS lookup failures, socket timeouts, etc. The default socket timeout was set to 30 seconds, which may be too low for some very slow sites. Should probably be tested. See also * * * Wikipedia:Dead external links